Three dimensional graphics request data commonly is processed in a computer system as a plurality of polygons having vertices. Each of the vertices have associated attribute data (e.g., color, transparency, depth, etc . . . ) that is utilized to rasterize pixels on a computer display device.
Vertices commonly are subjected to a plurality of different types of geometry calculations prior to being rasterized. Common functions typically include addition and multiplication functions. Specialized geometry accelerators often are utilized to perform such functions. Additionally, some transcendental functions commonly are required in vertex processing. Such calculations, for example, may be to determine an inverse square root of a number, or 2 raised to a power. Many geometry accelerators include a lookup table for each transcendental or elementary used function. Each lookup table typically has accompanying interpolation hardware for enhancing the accuracy of the transcendental functions by interpolating the results of the lookup table.